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Generation I Glitch Discussion

What causes a glitch color layer (glitch screen)? - Page 1

What causes a glitch color layer (glitch screen)?

Posted by: Torchickens
Date: 2017-05-14 14:02:01
I've been looking just a little into glitch color layers (known as glitch screens on Bulbapedia). Does anybody know what causes the glitch color layer effect for glitch Pokémon like X - x,?

I wonder whether there is a data structure that dictates this for each family of some sort.

I found this in the disassembly but couldn't find anything else sadly.


; super game boy palettes
const_value = 0

const PAL_ROUTE    ; $00
const PAL_PALLET    ; $01
const PAL_VIRIDIAN  ; $02
const PAL_PEWTER    ; $03
const PAL_CERULEAN  ; $04
const PAL_LAVENDER  ; $05
const PAL_VERMILION ; $06
const PAL_CELADON  ; $07
const PAL_FUCHSIA  ; $08
const PAL_CINNABAR  ; $09
const PAL_INDIGO    ; $0A
const PAL_SAFFRON  ; $0B
const PAL_TOWNMAP  ; $0C
const PAL_LOGO1    ; $0D
const PAL_LOGO2    ; $0E
const PAL_0F        ; $0F
const PAL_MEWMON    ; $10
const PAL_BLUEMON  ; $11
const PAL_REDMON    ; $12
const PAL_CYANMON  ; $13
const PAL_PURPLEMON ; $14
const PAL_BROWNMON  ; $15
const PAL_GREENMON  ; $16
const PAL_PINKMON  ; $17
const PAL_YELLOWMON ; $18
const PAL_GREYMON  ; $19
const PAL_SLOTS1    ; $1A
const PAL_SLOTS2    ; $1B
const PAL_SLOTS3    ; $1C
const PAL_SLOTS4    ; $1D
const PAL_BLACK    ; $1E
const PAL_GREENBAR  ; $1F
const PAL_YELLOWBAR ; $20
const PAL_REDBAR    ; $21
const PAL_BADGE    ; $22
const PAL_CAVE      ; $23
const PAL_GAMEFREAK ; $24

Re: What causes a glitch color layer (glitch screen)?

Posted by: Caveat
Date: 2017-05-14 14:58:46
I've always wondered why family 205 in R/B turns certain parts of the screen red, despite the fact that there isn't red in its sprite…

Are those two problems even related?!

Re: What causes a glitch color layer (glitch screen)?

Posted by: Torchickens
Date: 2017-05-14 15:15:44

I've always wondered why family 205 in R/B turns certain parts of the screen red, despite the fact that there isn't red in its sprite…

Are those two problems even related?!


That's interesting. For me family 205 in Red only has the black glitch color layer.

In Yellow though it seems 0xC1 (family 205) has a black glitch color layer in Super Game Boy mode and a black/red glitch color layer in Game Boy Color mode.

So today I learned glitch color layers can be found in both Super Game Boy mode and Game Boy Color mode in the same game.

Re: What causes a glitch color layer (glitch screen)?

Posted by: Caveat
Date: 2017-05-14 15:50:51
I should note that I got that information on Bulbapedia I have only caught family 205 on Virtual Console, which (naturally) doesn't have color.

Re: What causes a glitch color layer (glitch screen)?

Posted by: Torchickens
Date: 2017-05-14 15:59:12

I should note that I got that information on Bulbapedia I have only caught family 205 on Virtual Console, which (naturally) doesn't have color.


I see.

I found the offset. ^^

https://hax.iimarck.us/topic/109/

The IDs I posted above are the same valid values for this database, and it seems it starts at No. 000 who has the (0x10 'Mew' palette), then No. 001-003 who have palette 0x16 [GREENMON].

May start doing research into what gives the glitch layers tomorrow.

It's a little tedious going through all the glitch Pokémon articles repeatedly to add the information but all that the GlitchDex needs left now is:

1. Glitch color layers
2. Catch rate
3. Actual type IDs
4. Base experience yield
5. Dimensions, pointer to front sprite and back sprite
6. Beginning byte

As well as the Gold/Silver/Crystal glitch articles.

Re: What causes a glitch color layer (glitch screen)?

Posted by: Caveat
Date: 2017-05-14 16:11:47
While I was looking at the Glitchdex page for RB:BF, I noticed that its sprite is purple for some reason…

I haven't seen that documented anywhere else, so I'm curious why it wasn't the "Mew color" it typically has.

Re: What causes a glitch color layer (glitch screen)?

Posted by: Torchickens
Date: 2017-05-14 16:31:09

While I was looking at the Glitchdex page for RB:BF, I noticed that its sprite is purple for some reason…

I haven't seen that documented anywhere else, so I'm curious why it wasn't the "Mew color" it typically has.


That is family 250's Super Game Boy palette which can be modified from the values beyond the aforementioned database. The palette ID is hex:54, which is outside of the range of valid IDs. At first I thought it was a copy of hex:14 (PAL_PURPLEMON used for purple Pokémon such as Nidoran, Nidorino and Nidoking), but this seems to be a completely different more vivid purple.

Re: What causes a glitch color layer (glitch screen)?

Posted by: Caveat
Date: 2017-05-14 17:22:59
If I knew how to modify the game without causing it to explode, I would totally make a list of all the invalid palettes…

Re: What causes a glitch color layer (glitch screen)?

Posted by: ISSOtm
Date: 2017-05-15 13:51:50
You should copy the pokered disassembly and re-write some code.
"Bit" easier.